Buggy code:
class DDMReader { private static final int DEFAULT_BUFFER_SIZE = 32767 ; private static final int MAX_MARKS_NESTING = 10 ; private static final int NO_CODEPOINT = - 1 ; private static final int EMPTY_STACK = - 1 ; private static final boolean ADJUST_LENGTHS = true ; private static final boolean NO_ADJUST_LENGTHS = false ; private static final long MAX_EXTDTA_SIZE = Long . MAX_VALUE ; private static boolean internalTrace = true ; private static final int [ ] [ ] tenRadixMagnitude = new int [ ] [ ] { new int [ ] { 1000000000 } , new int [ ] { 232830643 , - 1486618624 } , new int [ ] { 54210108 , - 1613725636 , - 402653184 } } ; private DRDAConnThread agent ; private CcsidManager ccsidManager ; private byte [ ] buffer ; private int pos ; private int count ; private int topDdmCollectionStack ; private long [ ] ddmCollectionLenStack ; private long ddmScalarLen ; private int dssLength ; private boolean dssIsContinued ; private boolean terminateChainOnErr ; private boolean dssIsChainedWithSameID ; private boolean dssIsChainedWithDiffID ; private int dssCorrelationID ; private int prevCorrelationID ; private int svrcod ; private DssTrace dssTrace ; private InputStream inputStream ; protected DDMReader ( DRDAConnThread agent , DssTrace dssTrace ) { } protected DDMReader ( CcsidManager ccsidManager , InputStream inputStream ) { } protected void initialize ( InputStream inputStream ) { } protected void initialize ( DRDAConnThread agent , DssTrace dssTrace ) { } protected boolean terminateChainOnErr ( ) { } protected boolean isChainedWithSameID ( ) { } protected boolean isChainedWithDiffID ( ) { } protected long getDdmLength ( ) { } protected boolean moreDdmData ( ) { } protected boolean moreDssData ( ) { } protected boolean moreData ( ) { } protected boolean isCmd ( ) throws UnsupportedEncodingException , DRDAProtocolException { } protected byte [ ] getBuffer ( ) { } protected int readDssHeader ( ) throws DRDAProtocolException { } protected void readReplyDss ( ) throws DRDAProtocolException { } protected int readLengthAndCodePoint ( ) throws DRDAProtocolException { } protected int readCodePoint ( ) { } protected void markCollection ( ) { } protected int getCodePoint ( ) throws DRDAProtocolException { } protected int getCodePoint ( int codePointCheck ) throws DRDAProtocolException { } protected byte readByte ( ) throws DRDAProtocolException { ensureBLayerDataInBuffer ( 1 , DDMReader . ADJUST_LENGTHS ) ; <START_BUG> return ( ( byte ) ( ( buffer [ ( ( pos ) ++ ) ] ) & 255 ) ) ; <END_BUG> } protected int readUnsignedByte ( ) throws DRDAProtocolException { } protected int readNetworkShort ( ) throws DRDAProtocolException { } protected int readSignedNetworkShort ( ) throws DRDAProtocolException { } protected short readShort ( int byteOrder ) throws DRDAProtocolException { } protected int readNetworkInt ( ) throws DRDAProtocolException { } protected int readInt ( int byteOrder ) throws DRDAProtocolException { } protected long readNetworkLong ( ) throws DRDAProtocolException { } protected long readNetworkSixByteLong ( ) throws DRDAProtocolException { } protected long readLong ( int byteOrder ) throws DRDAProtocolException { } protected float readFloat ( int byteOrder ) throws DRDAProtocolException { } protected double readDouble ( int byteOrder ) throws DRDAProtocolException { } protected BigDecimal readBigDecimal ( int precision , int scale ) throws DRDAProtocolException { } byte [ ] getExtData ( boolean checkNullability ) throws DRDAProtocolException { } byte [ ] getExtData ( long desiredLength , boolean checkNullability ) throws DRDAProtocolException { } private void readDSSContinuationHeader ( ) throws DRDAProtocolException { } private boolean isEXTDTANull ( ) throws DRDAProtocolException { } private int packedNybblesToInt ( byte [ ] buffer , int offset , int startNybble , int numberOfNybbles ) { } private long packedNybblesToLong ( byte [ ] buffer , int offset , int startNybble , int numberOfNybbles ) { } private int [ ] computeMagnitude ( int [ ] input ) { } protected boolean readBoolean ( ) throws DRDAProtocolException { } protected String readEncryptedString ( DecryptionManager decryptM , int securityMechanism , byte [ ] initVector , byte [ ] sourcePublicKey ) throws SQLException , DRDAProtocolException { } protected String readString ( int length ) throws DRDAProtocolException { } protected String readString ( int length , String encoding ) throws DRDAProtocolException { } protected String readStringData ( ) throws DRDAProtocolException { } protected String readStringData ( int length ) throws DRDAProtocolException { } protected String readLDStringData ( String encoding ) throws DRDAProtocolException { } protected String readString ( ) throws DRDAProtocolException { } protected byte [ ] readBytes ( int length ) throws DRDAProtocolException { } protected byte [ ] readBytes ( ) throws DRDAProtocolException { } protected void skipBytes ( int length ) throws DRDAProtocolException { } protected void skipBytes ( ) throws DRDAProtocolException { } protected void skipDss ( ) throws DRDAProtocolException { } protected void clearBuffer ( ) throws DRDAProtocolException { } protected String convertBytes ( byte [ ] buf ) { } private void adjustLengths ( int length ) { } protected String readCmdString ( int length ) throws UnsupportedEncodingException , DRDAProtocolException { } protected String readCmdString ( ) throws UnsupportedEncodingException , DRDAProtocolException { } private void ensureALayerDataInBuffer ( int desiredDataSize ) throws DRDAProtocolException { } private void ensureBLayerDataInBuffer ( int desiredDataSize , boolean adjustLen ) throws DRDAProtocolException { } private void compressBLayerData ( int continueDssHeaderCount ) throws DRDAProtocolException { } private void shiftBuffer ( byte [ ] destinationBuffer ) { } private void ensureSpaceInBufferForFill ( int desiredSpace ) { } private void fill ( int minimumBytesNeeded ) throws DRDAProtocolException { } private void trace ( String msg ) { } protected String toDebugString ( String indent ) { } protected byte getCurrChainState ( ) { } }

Fix:
return buffer [ ( ( pos ) ++ ) ] ;